1. Field of the Invention
This application is directed to multifunctional antiwear/antioxidant additives for lubricants and to improved lubricant compositions containing same. The additive products of this invention are derived from the reaction of organic or metal salts of diorganodithiocarbamic acids with hydrocarbylbenzenesulfonyl derivatives.
Ashless dithiocarbamates are a valuable class of compounds as potential replacements for their metal structural analogs in the lubricant industry and in a market in which the prevailing and projected tendency favors non-metallic additives. The products of this invention have demonstrated excellent antioxidant and antiwear effectiveness in lubricating oil compositions and have the potential advantage over the metal analogs, of better solubility in, and compatibility with, a variety of base stocks. Another advantage of these sulfonyl derivatives is the potential reserve alkalinity needed to neutralize acidic by-products while in service.
It has now been discovered that the products obtained from the reactions of dithiocarbamic acid salts and benzene sulfonyl derivatives, lubricating compositions containing same, and use of such compositions provide the unexpected & highly desirable benefits itemized below.
2. Description of Related Art
A variety of dithiocarbamate-derived compounds are known to be useful in lubricant compositions. For example, U.S. Pat. No. 4,919,830 is directed to dihydrooarbyl dithiocarbamate-derived organic phosphates which have been found to be effective multifunctional additives for various lubricant media and U.S. Pat. No. 4,859,356 is directed to reaction products derived from amine or metal salts of N,N-diorganodithiocarbamic acids with alkylthiiosulfinyl halides useful as multifunctional additives in lubricating oil compositions.
More specifically it has been found that products derived from the reaction of the organic or metal salts of N, N-diorganodithiocarbamic acids with alkylbenzenesulfonyl halides impart excellent multifunctional antiwear and antioxidant protection t lubricating oil compositions.